Improved explosive compound



totes strut @ffir ALFRED NOBEL, OF HAMBURG, GERMANY, ASSIGNOR TO JULIUS BAND MANN, OF SAN FRANCISCO, CALIFORNIA.

Letters Potent No. 78,817, dated May 26,1868.

IMPROVED EXPLOSIVE COMPOUND.

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TO ALL WHOMYIT MAY eonenmvr Be it known that I, ALFRED NOBEL, of the city of Hamburg, Germany have invented a. new and useful Composition of Matter, to wit, on Explosive Powderif The nature of the invention consist's'in'forining out of two ingredients long known, viz, the explosive substance nitro-glyc n'ine, and on iriexplosirc porous substance, hereafter specified, e compositionwhich, without losing the greet explosive power of'nitro-glycerine, is very much altered as toils explosive'and other propertics, being fur more safe and convenient for transportation, storage, and use, than nitro-glycerine.

In general terms, my invention consists in mixing with nitro-glyeerine a. substance which possesses a very great absorbent capacity, and which, at the some time, is free from any quality which will decompose, destroy, or injure the nitro-gly cerinc, or its explosivehcss. I

It is undoubtedly true, as, a general rule, thatnitro-glyccrine, when mixed with another substance, pose sesses less concentration of power than when used. alone; but while the safety of the minor (to prevent leakage into seems in the rock) prohibits the use of nitro-glyocrine without ctrtriclges, which latter must of course be somewhat less in diameter than the boro-holes which are to contain them, the powder herein (lcscribed cun be made to form n. semi-pasty mass, which yields to the slightest pressure, and thus can be made tolill up the borehole entirely. Practically, therefore, the miner will have as much nitro-glyceriuc in the sarne hcight of bore-' hole with this powder as with nitro-glyoerine in its pure state.

This is the real character and purpose of my invention; and in order to enable others skilled in theort to which it nppertsins (or with which it is most nearly connected) to make, compound, and 'use thc-ssmqI will' proceed to describe the-same, and alsothe manner and process of making, compounding, and using it, in full, clear, and exact terms.

The substance which most fully meets the requirements above mentioned, so for us I know or have been able to ascertain from numerous experiments, is o certain kind of silicious earth or silieic acid, found in various ports of the globe, and known under the several names of silicious marl, tripoli, rotten-stone, &o. The par ticular variety of this material which is best for my compound is homogeneous, has a low specific gravity, great absorbent capacity, and is generally composed of the remains of infztsorz'a.

So great is the absorbent capacity of this earth, that it will take up about three times its own weight ob nitno-glycerine .und still retain its powder-form, thus leaving the nitro-glyeerine so compact .a'nd concentrated us to have very nearly its original explosive power; whereus,-if another substance, having as less absorbent capacity, is used, a correspondingly less proportion of nitro-glyeerino will be absorbed, and the powder be conrespondingly weak or wholly inexplosivc. I

For example, most chalk will take but about fiftecnpor cent-of nitro-glycerine and retain its powder-form. Twenty per cent. will reduce it to a paste.

Porous charcoal has also a considerable absorbent capacity, but it has the defect of being itself a combostible material, and also of less elasticity of its particles, which renders it easy to squeeze out a part of its intro-glycerin.

i The two materials are combined in the following manner:

The earth, thoroughly dried'and pulverized, is placed in a wooden vessel. To it is introduced the nitro glycerine in a steady stream so smell-that the two ingredients can be kept thoroughly mixed. p

The mixingmoy'be effected by the naked hand, or by any proper wooden instrument used in the hand, or by wooden machinery v Sufiicient of nitroglycerin should be used to render the compound explosive, but not so much as to change its form of powder to a liquid or-pusty consistency.

Practically, about eixtyports, by weight, of nitro-glycerine to forty of earth, forms the useful minimum,"

and seventy-eight parts, by weight, of nitro-glyccrlnc to twenty-two of earth, the useful maximum of explosive Between these two extremes the composition will be explosive powder, an and its explosive power greater, asthe relative proportion of the nitro-glycerine is greater.

The proportions, by weight, of seventy-five of nitro-glycerine to twenty-fiveof earth, gives a powder: 8

power. The former has a perfectly dry appearance, the latter is pasty. i dit will be more easily exploded,

well adapted to ordinary practical purposes as that from any proportions 1 am now able to 'fl'llllllr untl crui'ln easily compressed to a specific gravity nearly equal tothat of pure nitro-glycerine.

When the mass has been intimately mixed and thoroughly incorporated by sti rubbed through a hair, silk, or brass-wire sieve, (iron corrodcs,) and any lumps which may remain are rubbed with a stilT-bristle brush till they are reduced and made to pass through the sieve.

. The powder is then finished and ready for use.

The fineness desired for. the powder wlil determinethcfincncss of the sieve to be used. The chief characteristic of this powder is its nearly perfect exemption from liability to accidental' or involuntary explosion. 1 7

It is far less sensitive than nitro-glycerine to concussion or percussion, and contained in its usual packing, (a wooden cash or box,) the latter may be smashed completely to pieces without any danger of an explosion.

Unlike gunpowder, in the open air or in ordinary packing, (a wooden cask or box,) it burns up, when set fire to, without exploding. It can, therefore, be harldlod;stored, and transported with less danger than ordinary gunpowder. it

When confin'ed in a. tight and strong enclosure it explodes by heat applied in any formwhen above the temperature of 360 Fahrenheit. Under all other circumstances it may be exploded-by some other'explosion in it or into it,

The most simple and certain method known to me of exploding it is as follows: I The end of a common blasting-fuse is inserted into a percussion-cap, and the rim oftheeap crimped tightly and firmly about the fuse by nippers, or other means, so as. to leave the fulminuting powder of the cup and th end of the fuse tightly and firmly enclosed together. The end'of the fuse, with the cup attached, is 'tllcr embedded in the powder-the more firmly, the more certain the explosion.

In blasting, the powder is pressed tightly about the cap and fuse, and tamping, of sand or other-proper material, added, and pressed burno't pounded in. A tamping firmly pressed is as $901 115. if rammed in the most solid manner.

The fuse explodes the cap, and this explosion explodes the powder. I will add here that by carefully packing the end-cf a. good fuse amidst the powderof'a charge enclosed, like it blasting chtrrge, in 15!.- sight plnemthe fuse alorie will explode the powder, especially if the powderis' strongly charged with nitro-glyceriuo. But this method of explosion requires too much care, and is too-uncertain to be depended upon or generally used. H

As before stated, the more strongly the powder is charged with nitro-glycerine the more easily it explodes. If, therefore, the powder contains a low proportion of nitro-glycerine, it is necessary to employ in its explosion a correspondingly long, strong, ahd heavily-charged percussion-cap, made especially for the purpose. For the sake of certainty of explosion it is better to use such a cap in all cases.

If the fire from the fuse comes ip contact with the powder .before the cap is exploded, wh ch is liable to occur if the fuse is leaky and the cap extends too far into the powder, a portion of the powder willbe burned before the explosion takcs place. To guard against this, the cap shouldonly be fairly inserted into the. powder,

and poor fuses wound next to the cap firmly with strong glued paper or hemp, or otherwise secured.

The bore-holes, as a practical but not absolute rule, should be about one-half the size, and the charge should be from one-fifth to one-tenth the quantity ordinarily used in gunpowder-blasting.

A very convenient form in which to use the powder is to pack it firmly in cartridges of strong paper.

Having thus described my invention, what I claim as new, and desire to secureby Letters Patent, is f The composition of matter, made substahtially of the ingredients and in the manner and for the purposes set forth.

ALFRED NOBEL.

Witnesses:

FR. '1. Pawns, Humn. Bnnrnn'rssex rring and kneading, is 

